Spatiotemporally optimized heterotopic transplantation of early-stage small intestinal organoids ameliorates murine ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease where achieving durable mucosal healing remains a critical clinical challenge. While intestinal organoids hold promise for UC repair, autologous colonic transplantation is severely hindered by limited biopsy availability and inflammation-impaired stemness. To overcome these limitations, we developed a spatiotemporally optimized heterotopic transplantation strategy utilizing early-stage small intestinal organoids at peak Lgr5+ stemness. In a dextran sulfate sodium (DSS)-induced UC mouse model, these highly regenerative grafts effectively ameliorated disease severity and restored structural epithelial barrier integrity. Mechanistically, mucosal healing is driven by a tripartite synergy encompassing direct functional epithelial replacement, paracrine immunomodulation to attenuate inflammation, and the subsequent restoration of gut microbial homeostasis. These findings circumvent the clinical barriers of autologous grafts, offering a potent, mechanism-driven strategy to reduce intestinal inflammation and restore tissue homeostasis.